This application is related to commonly assigned, co-pending application Ser. No. (08/984,510), entitled "Method of Producing Customizable Automotive Electronic Systems", which was filed concurrently herewith.
The present invention relates in general to user controls for electronic devices and systems, and more specifically to the reprogrammable assignment of user controls for automotive electronic systems and subsystems (e.g., the push buttons and knobs on a car radio) to the specific features and functions which are to be performed in response to the user controls.
Electronic devices and systems can be produced having lower per unit cost when the device is mass produced at high volumes. In many instances, the per unit cost of manufacture continues to fall as the total number of devices increases. Nevertheless, variety must be maintained even in products of a single type (e.g., radios) for purposes of 1) product differentiation in terms of styling and/or feature content or 2) differences in product requirements in various local marketing regions or countries. Maintaining product variety reduces economies of scale and creates complexity at manufacturing plants. For example, a manufacturer of car radio subsystems may need to manufacture several different radio models because of styling differences between radios installed in various models of vehicles and because different geographic markets may require different radio features to be controllable. Each radio model may have different hardware and software which is unique to that model and which requires separate engineering development and separate manufacturing support.
An electronics manufacturer may often find it necessary to change the detailed configuration of the user control elements of existing audio, driver information, or other electronic subsystems in order to integrate the subsystem in other environments such as other car models or in response to varying market requirements. Prior art design practices use fixed assignments of user control elements to particular subsystems functions. The software and hardware design of a subsystem must be significantly modified in order to change the assignment of a user control element to a different subsystem function or to modify the number and/or layout of user control elements. Each alteration, however small, results in a new and unique part which has its own part number and associated logistical requirements. Each change requires unique development resources, testing, and manufacturing support. The cost of the modification process is significant and the resulting electrical components are not interchangeable.